In general, a probe card is configured to provide a number of contact probes to stand on a wiring board, and used in an inspection process of semiconductor integrated circuits. A semiconductor integrated circuit is inspected by bringing contact probes into contact with corresponding electrode pads of the semiconductor integrated circuit formed on a semiconductor wafer and electrically connecting the semiconductor integrated circuit and an external device to each other. When doing this, in order to accommodate variations in the heights of contact probes and electrode pads and thereby surely electrically connect the contact probes and the electrode pads, a process to press the contact probes against the electrode pads is performed, correspondingly. This process is called overdrive.
It is known that some type of conventional probe cards include a probe guide adapted to support contact probes. A probe guide is formed with a number of guide holes, and the contact probes are inserted into corresponding guide holes and supported movably in a direction of the insertion. By providing such a probe guide, the tips of the contact probes can be accurately positioned.
The conventional probe guide is made of a ceramic plate, and the guide holes are typically formed by drilling or laser machining. However, in recent years, as the degree of integration of a semiconductor integrated circuit has been increased, it has been demanded to decrease the diameter of guide holes and the pitch between adjacent guide holes, and as a result, the formation of the guide holes by drilling or laser machining is becoming difficult. For this reason, it is proposed that guide holes are formed in a silicon plate by etching to fabricate a probe guide; however, the problem of being difficult to ensure the strength of the probe guide exists.
Each of the guide hole formed by the etching is such that the inner wall surface thereof is tapered, and thereby opening diameters at both ends are made unequal. As a result, the thickness of a partition wall separating adjacent guide holes changes in a thickness direction of the guide plate, and is thinner on a large diameter side than on a small diameter side. That is, the thickness of the partition wall that is thinned due to the decrease in the pitch is further thinned by the tapered guide holes, and consequently the strength of the probe guide is reduced. In particular, since silicon that is easy to etch is brittle as compared with ceramic, ensuring the strength is difficult. In addition, when the inner wall surfaces of the guide holes are worn by sliding friction with corresponding contact probes at the time of inspection, the partition walls are more likely to be broken, and therefore the problem of being difficult to ensure the abrasion resistance of the probe guide exists.